"Drinking tea is better for you than drinking water."
A study in the European Journal of Clinical Nutrition finds that drinking three to four cups of tea per day can reduce one’s chances of having a heart attack, and possibly help protect against some cancers. The study’s author, Carrie Ruxton of Kings College London, challenges the common perception of tea as dehydrating, insisting that tea rehydrates just as well as water does:
Drinking tea is actually better for you than drinking water. Water is essentially replacing fluid. Tea replaces fluids and contains antioxidants so it's got two things going for it.
There is, however, research suggesting that tea can impair the body's ability to absorb iron from food--people at risk of anemia should avoid drinking tea around mealtimes.
Dr. Ruxton stressed that the study—despite its sponsorship by The Tea Council—was carried out independently. [Source]
This study comes on the heels of two reports about the benefits (or risks, as they may be) of coffee consumption. Check out truthdig for more on that mixed message.